Process for preventing the formation of boiler-scale.



T. BRKZDA, E. RICHTER & A. SOH'IiGKHBR. PROCESS FOR'IREVBNTING THE FORMATION OF BOILER SCALE. APPLI'OATION FILED SEPT. 19, 1912.

' 1,059,431, Patented Apr. 22, 1913.

UNITED i sra'rns rafrnnrr ora ion.

THEODOR BRAZDA, OFPILSEN, AND EMIL RICHTER AND ALBERT SCHU'CKHER, OF

VIENNA, AUSTRIA-HQNGARY. i

PROCESS FOR PREVENTING THE FORMATION OF BOILER-SCALE.'

Specification of Letters Iatent.

Patented Apr. 22, 1913.

Application filed September 19,1912. Serial No. 721,281.

To all Ill/107M 1'1- may concm'n:

Be it known that We, Tuuonon Bna'tzna, subject of the Emperor of Austria-Hungary, residil'ig at Pilsen, Bohemia, Austrian Hungary, and EMIL RICIt'l'I-IR and Amnnrr Sonijrcminn, subjects of the Emperor of Ans trier-Hungary, residing at Vienna, Austria- Hungary, haveinvented certain new and useful Improvements in a Process for Proventing the I ormation ot l ioiler t'lcale, of which the following is a specificatimi.

The object of the U. S. Patent No. 925253) is a process for preventing the toi'mation of boiler scale in which the feed water, without addition of chemicals, is boiled with simultantuuls vigor stirring in a container, which is not quite filled, which is closed on all sides and does not stand. under the prcssure of the feed pump or the boiler, with the object of precipitating part of the sub stances causing hardness in the torn) o'l' a fine mud, suspended in the water. when .the feed Water is introduced into the boiler with this suspension or the precipitate obtained therefron'i alone. The necessary energetic motion of the water (lining boiling can be eti'octed either by the steam itself or with the aid of mccl'ianical stirrcrs. This process is based on the fact that the n1ierocrystalline precipitate which results in this treatment is capable, on account ot its particular condition, of preventing deposition on the walls of boilers and the like, because the prccip'r tate which commences to crystallize out in the boiler at increasing concentraticm forms no boiler scale under the inductive of the sus pension which has been added. (in the contrary, those precipitates are also o'l. great fineness and mobility, they follow all the movements of the water and at a certain t1vcr-concentration form a soft, pasty sludge, which can he removed by periodic drawing Off from the boiler.

It was originally atten'ipted, to attribute the surprising action of the process to the easily mobile tine particles of the suspension suspended in the boiler water ctmtinually rubbing on the walls of the boiler and on the deposits in course of it'ormation in the boiler. whereby these deposits were not allowed to lie still and were thus hindered from bccour ing solid. Another more plausible attempt at explanation is that these mostlincly divided crystals previously present in the boiler water serve in a certain manner as crystallizatimi points or crystal nuclei for the substances causing permanent hardness, which separate out later in the boiler. The suspensirms preci pitatcd by boiling the Water with vigorous stirring mainly consist of bicarbonates. The substances causing the permanent hardness, in which sulfates are priiuzipally concerned, in consequence of their great solubility first begin to separate out, when the soiution has attained the corresponding degree oi concentration by evaporation and enrichn'ient in consequence of lresh addition ot' water containing sulfates.

lhc small crystals oi: carbonate introduced into the boiler water, which take part in all.

the movements of the smile, attract to them solves the sulfates, which crygstallize out in sonuurhat the same nninncr as sugar begins to crystallize out. from a saturated solution on to a crystal which is hung therein. Thus by the excessively tine, carbonate crystals suspended in all parts of the boiler Water the sulfates are actively prevented from forming a solid de osit on the walls of the boiler.

The present invention has for its object a further development of this process. This l'urther development of the original process aims first at carrying out by the simplest possible means the process oifboiling the water with' energetic stirring during continuous wm'lting. To this end according to the present invention, the water which is to be treated, is added continuously, or intermittently at short time-intcrvals, to a closed container, which is not wholly filled, and is led from the container in the same manner, and as it flows is boiled and kept in motion so vigorously that the precipitate settles out in the desired fineness. The water is usually iutrodtured by a pump or by a suitable high reservoir. The boiled watercan be likewise led from the container to the boiler by a pump unless it preferred to feed the watcr into a collector and to feed it to the boiler therefrom.

ln treatnu-nt in continuous workingin order to secure the deposition of the precipitate in the required microerystalline condition and line division, on which indeed the working of the whole )r'ocess depends, it. is advisable to conduct this treatment of the water in several consetaitive phases.

0 I this end the process can be carried out -in a .another. after the other can also be employed.

sinfgle; container in which suitably formed ba e-plates are disposed which force t the water during the energetic stirring to run in a current of heating places situated one after But several containers, placed one The energetic stirring of the water, which isessential for the process, can be obtained in variouaways, as was mentioned at the beginning. If the source of heat is outside the container the vigorous movement of the,

water'is'efiected by the aid of mixing wheels, stirrers or the like, disposed inside the-container. If the heating of the water is etfected by allowing steam to pass directly intoit, this steam, by means of suitable devices, can simultaneously serve to bring about the requisite energetic motion.

Devices have been previously'proposed to effect the prior warming of the water by direct. admixture of vsteam fwith the feed water, (for example, by leading in the steam in fine jets, or withthe'so-called noiseless heaters), but thesehave always been con .cerned only with an improvement in giving up heat to the water. To ascribe directly to the steam the function'of a stirring medium has first been proposed toward the solution of the problem of generating,'by intensely dashingthe water particles together, a precipitate of microcrystalline condition, whose finest particles are first rendered distinctly visible on considerable magnifications, which turbidity, whether suspended in the b.oiler water or added as such to the boiler water, forms anactive means for preventing the formation of boiler scale;

As a further development of the process it has proved advantageous to cause the adm1ss1on into the water container steam or water or both to take place In intermittent pufls (pulsating). The pulsating,

inicomparison to the continuous steam 1nflow, results in an increased agitation of the water. The pulsating, in comparison to the continuous, inflow of water causes the pressure variations in the container to take place within wider limits, whereby the pulsation of the current of steam is essentially increased. This ulsating inflow of steam or water pan be e ected either'with the aid of mechanicalmeans or it can be brought into .play by'the pressure variations occurring inaction of the'steanr flowing into the water by combination'with mechanical stirring collecting in of the means, in that the steam pipe fixed in the container is provided with stirring vanes and arranged as a stirring axle.

The gases chemically bound in the water i and evolved in the precipitation process are driven out by boiling the water under vigorous stirring,

above the level of the liquid and can thereupon be blown process, for it avoids the attack on the material of the boiler which otherwise takes place, and, avoids the origination lot corrosion." Now it has been found advantageous, especially in carrying out the process in continuous working, to allow this blowing off of the gases to occur periodically, c. e. in putts. In this way the gases which are not-immediately at the blow-oft opening and those which are in the deeper layers are carried off by the putting actionpso that the water passes into the boiler completely freed from air and, gases. The periodic blowing-0E can be eliected'by hand or automatically by suitable devices at the requisite tuneintervals. v To carry out the process, according to this inventionthe mechanism disclosed in the accompanying drawing may be utilized but 1t is to be understood that the device shown is only illustrative and may be modified as required under varying conditions. A'containcr a is connected by means or the pipe g to a source'of water supply and the pipe 0? supplies steam to the container a from a suitable source. The pipe (l terminates-'- within the container in a section a which is provided with a plurality of suit-ably situ-- ated exits e. A plurality of intermediate walls or battle plates I) force the water to traverse a number of chambers in series as the untreated water flows from the admission opening to the discharge opening and prevent the water from leaving the container a before being sufiicientlyboiled and treated. The pipe g'discharges into a space outv of,the container. There a is distinct importance in this action 111 the the principal quantity of which the upper part of the container h which separated from the other space of i a communicates with the chamber 72 and contains a piston k the pressure prevailing in the chamber is and the piston face is balanced against this pressure by a suitable spring Z or an equivalent device. A rod m connects the piston with a. cut-off valve n controlling the steam supply from the pipe (Z. When the steam pressure within the container a reaches a sufficient value to operate the piStonk the rod m is moved against the tension of the spring 5 and the cut-ot't'n is closed preventing further admission of steam. As soon asthc A casing 7' on the exterior of the container one face of which is under steam is condensed in the space It by the inflowing water the pressure rapidly diminishes there so that the spring Z predominates and the valve nis opened, againadmitting steam. The space It being separated-from the rest of the container or, and proportionately smallerfia quicker action of the water on the steam is obtained to brin about a frequent change of pressure and thereby also a sufficiently rapid pulsation of the steam. The water supply is also regulated in a similar manner and its admission may be pulsated by the provision of the pipe 111 communicating with the chamber h and with the chamber j onthe exteriorof thccont-ainer a. Piston 7s and spring Z work within the casing j to operate a rod m for openingand closing valve 12/ in the Water supply pipe 9'. By this means both the steam and water supply are regulated by the pressure prevailing in the chamber 12. This regulation takes place in such a manner that with a predetermined reduction in pressure in the chamber h, the steam valve n is opened and a corresppndin increase in pressure opens the water valve 11. by the pulsating inflow of the steam and water and essentially intensive agitation of the water is attained.

The boiled water 'leay es the container a at the lower endthrough the pipe p provided with a cut-off valve 0. A filter 7' may be provided to hold back the precipitated suspended matter. A means for drawing ofi' the mud .ay also be provided. A plpe t with a cut-oil valve v serves to permit the blowing oil of the gases collecting in the upper part of the container a.

Claims.

1. The herein described method of preventing the formation of boiler scale which consists in simultaneously admitting pater I v A J to and drawing it oil from a container and in ecting steam directly into said water at a.

plurality of points as it passes through'said continuous treatment of feedwvatei' as it moves through a container between the source of supply and the boiler to which it is fed which comprises simultaneously heating;

and vigorously agitating substantially all of the articles of the entire body of water in the container as the entire body moves through. the container on its Way to. the

boiler whereby the scale forming substances are separated-and suspended in said Water in a finely divided state before being introduced into the boiler with the water.

The herein described method of reventing the formation 0 boiler scale w ich consists in admitting water to and drawing it off from a contalner and injectinglsteam directly rnto said water as 1t passes t rough said container to simultaneously heat and vigorously agitate said water, and in rapidly and intermittently interrupting the flow of fluid entering the container to cause pulsations of said fluid and assists in the agitation of the water.

y In testimony whereof we have ailixed our signatures in presence of two witnesses.

THEODOR BRAZDA. EMIL RICHTER. ALBERT soHUcKHER.

Witnesses:

AUGUST Fooonn, DR. Riel-[Ann PECK. 

